- Why in news
- On 6 October 2026, the Ministry of Science & Technology announced a ten-year study of the blazar OJ 287, led by ARIES, Nainital, which gives new clues about its binary black hole system.
- What it is
- OJ 287 is a blazar about 4 billion light years away. It holds two supermassive black holes orbiting each other in a roughly 12-year orbit. Its brightness shows a double-peaked outburst pattern, which astronomers use to track the orbit.
- What a blazar is
- A blazar emits powerful plasma jets moving at near light speed and pointed toward Earth. Its emission varies fast across the spectrum, from radio to gamma-rays.
- Discovery of the periodic pattern
- The periodic double-peaked behaviour was found in 1988 by Finnish scientists using optical records going back to 1880.
- Who ran the study
- The study was coordinated by ARIES, Nainital, an autonomous institution of the Department of Science and Technology, and led by Dr. Alok C. Gupta.
- Scale of collaboration
- The team had 106 scientists from 18 countries and 48 institutions, using two dozen telescopes from 2015 to 2025.
- Central black hole mass
- The central black hole mass was estimated at no less than 3.89 billion solar masses, from the [O III] emission line width.
Don’t confuse with Blazar vs quasar: Both are active galactic nuclei powered by supermassive black holes. A blazar is the type whose jet points toward Earth, which makes it bright and rapidly variable.
Don’t confuse with Multimessenger astronomy vs multiwavelength astronomy: Multiwavelength astronomy uses different bands of light only. Multimessenger astronomy also combines gravitational waves, neutrinos and cosmic rays.
Science and technology: 57 Prelims questions since 2013; most test the concept behind the news, not the news itself. In Mains, 12 news-triggered questions.
Why it matters
- Gives a long, dense optical record to test models of binary supermassive black hole orbits.
- Supports multimessenger astronomy, linking light with gravitational-wave signals.
- Shows Indian institutions (ARIES, DST) leading global astronomy collaborations.
Problems
- Binary black holes are unresolved points, so orbits must be inferred from brightness patterns.
- Long-term monitoring needs many telescopes in different time zones and sustained coordination.
Way forward
- Continue multiwavelength monitoring to study relativistic jets and the smaller black hole.
- Link electromagnetic data with gravitational-wave observations.
Put in your answer
Global collaboration example: 106 scientists from 18 countries used two dozen telescopes over 2015-2025, led by an Indian institute.
Multimessenger astronomy: It combines light, gravitational waves, neutrinos and cosmic rays from the same source.
UPSC’s own questions that come close to this issue, from our Prelims and Mains banks.
No practice question for this one; the card may still help an answer. Why: Astronomy concept topic, but a single study with few testable facts. Sci-tech is 17% of Prelims, mostly concept-based.
Worth revising until Prelims 2028: most news questions come within two years of the event.